From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752254AbcHHNkW (ORCPT ); Mon, 8 Aug 2016 09:40:22 -0400 Received: from mx2.suse.de ([195.135.220.15]:42629 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752116AbcHHNkV (ORCPT ); Mon, 8 Aug 2016 09:40:21 -0400 Date: Mon, 8 Aug 2016 15:40:01 +0200 From: Borislav Petkov To: "Rafael J. Wysocki" Cc: Linux PM list , Thomas Garnier , the arch/x86 maintainers , Linux Kernel Mailing List , Yinghai Lu , Thomas Gleixner , Ingo Molnar , "H . Peter Anvin" , Kees Cook , Pavel Machek , Kernel Hardening , Borislav Petkov Subject: Re: [Resend][PATCH] x86/power/64: Always create temporary identity mapping correctly Message-ID: <20160808134001.GC29757@nazgul.tnic> References: <2206547.eDj3RJQyE5@vostro.rjw.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <2206547.eDj3RJQyE5@vostro.rjw.lan> User-Agent: Mutt/1.6.0 (2016-04-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Aug 08, 2016 at 03:31:31PM +0200, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki > > The low-level resume-from-hibernation code on x86-64 uses > kernel_ident_mapping_init() to create the temoprary identity mapping, > but that function assumes that the offset between kernel virtual > addresses and physical addresses is aligned on the PGD level. > > However, with a randomized identity mapping base, it may be aligned > on the PUD level and if that happens, the temporary identity mapping > created by set_up_temporary_mappings() will not reflect the actual > kernel identity mapping and the image restoration will fail as a > result (leading to a kernel panic most of the time). > > To fix this problem, rework kernel_ident_mapping_init() to support > unaligned offsets between KVA and PA up to the PMD level and make > set_up_temporary_mappings() use it as approprtiate. > > Reported-by: Thomas Garnier Reported-by: Borislav Petkov > Suggested-by: Yinghai Lu > Signed-off-by: Rafael J. Wysocki > Acked-by: Yinghai Lu > --- > > This is sort of urgent, because hibernation doesn't work with KASLR on x86-64 > in 4.8-rc1 AFAICS and this should make them work together again. > > Unless anyone sees any problems with it, I'll queue it up for 4.8-rc2. > > Thomas, would it be possible to test it with KASLR enabled, please? Is that the only patch which needs to be tested? Ontop of which tree? CONFIG_RANDOMIZE_MEMORY blew up s2d on my laptop here so I'll run it once I have the required info from you :) Thanks. -- Regards/Gruss, Boris. ECO tip #101: Trim your mails when you reply. SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg) --